The present invention relates to a lighter of the type used by consumers to light cigarettes, cigars, and pipes and more particularly to a lighter using butane fuel to create a directed flame.
Lighters have been known and used for many years. One type of conventional lighter uses a fuel which is liquid but volatile at normally encountered environmental temperatures (about 25° F. to 90° F.). This type of lighter comprises a fiber filled fuel reservoir surrounded by a metallic case. A wick extends from the fiber filled fuel reservoir into a combustion chamber outside of the fuel reservoir which is surrounded by a wind screen. On one side of the combustion chamber, a rotatable steel wheel having a rough surface rests against a flint which is spring biased into engagement with the steel wheel. When the steel wheel is rotated, particles of the flint are separated from the flint body, become incandescent and are projected into the combustion chamber near the fuel soaked wick. Fuel vapor evaporating from the wick is ignited by the sparks created by the flint and steel at the location surrounding the wick where the fuel vapor mixes with air. This produces a flame surrounding the wick. The combustion created by this type of lighter is called “post mix” combustion because the fuel and air is mixed in the combustion chamber at the point of combustion.
The word “flint” is used herein to mean the commercially available consumer product called “flint” or in the plural, “flints”. This product is not normally the historical stone “flint” but is a manufactured product including rare earth metals such as cerium and other elements. These “flints” are often sold in a package of several units formed into small cylinders for use with cigarette lighters and are widely commercially available. They will not be further described herein. It will be appreciated that the word flints and the word flint are used in the specification to mean these products, variations of these products and other commercially available products which, when abraded with a serrated steel or iron wheel, produce incandescent particles capable of initiating combustion of a fuel and air mixture.
The flint and steel or iron wheel ignition system has an advantage when compared to many other systems in that a single stroke by the thumb against the iron wheel produces many incandescent sparks of a temperature sufficient to ignite a fuel and air mixture. As many sparks are produced, the likelihood of an incandescent spark interacting with an appropriate fuel air mixture volume is high and reliable operation becomes more likely.
Another type of conventional cigarette lighter uses butane fuel. “Butane” fuel is used herein to mean a fuel which, at normally encountered atmospheric temperature and pressure, is gaseous if unrestrained. However, “butane” fuel is easily compressed into a liquid state at normally encountered atmospheric temperature and pressure conditions. Thus, butane fuel can be sold in the pressurized liquid state which is easily handled by consumers and loaded into a sealed chamber in a cigarette lighter. When a vent or nozzle on such a sealed container of butane is opened, butane gas will be released and butane liquid within the container or reservoir will quickly turn into a gas so long as the pressure is reduced to atmospheric. The chemical butane answers this description. However, butane gas mixed with other organic chemicals in minor amounts will also meet this description. The word butane is used herein to mean commercially available lighter fuels and other available similar fuels answering the same functional description.
Many conventional butane lighters comprise a reservoir of butane fuel connected to a lever operated valve which is in turn connected to a mixing arrangement adding air to the fuel which is fed to a nozzle. A piezoelectric igniter is used. A user operates the lighter by depressing a button with a thumb which opens the fuel valve and operates the piezoelectric igniter. Fuel passes through the fuel valve into the mixer where it is mixed with air and then exits through the nozzle as a jet. The single spark created by the piezoelectric igniter then ignites the flame providing a torchlike blue flame. The flame is different from a post mix flame in that it is ignited and burns as a premixed mixture of fuel and air in the combustion chamber. The mixing of fuel and air occurs prior to combustion. The resulting combustion and flame are described as premix. This results in a more forceful directable flame. Flint and wheel igniters do not operate well with these premix flame producing structures. It is thought that the higher velocity of the gases exiting the nozzle as a jet reduces the effectiveness of flint and wheel igniters. Piezoelectric igniters create only a single spark on each actuation. Such lighters do not always ignite in response to actuation. Reliability needs improvement. However, premix lighters do provide a hotter, more directable and stable flame. The premix flame is also less likely to be extinguished by wind. Premix nozzles and burner parts are more easily clogged by dirt or debris. Piezoelectric igniters are more expensive than flint and wheel igniters.
A third type of lighter uses butane in a reservoir under pressure and a flint and wheel igniter. The butane reservoir is connected to a valve which is in turn connected to a nozzle. When the user wishes to operate the lighter, he uses a thumb to rotate the wheel and then to press a thumb button which opens the butane valve. The butane gas exits through the valve and the nozzle into a combustion chamber where it mixes with air and forms, after ignition, a post mix flame similar to what is seen with a liquid fuel lighter. The post mix gasses are ignited by the incandescent flint particles just as with a conventional liquid fuel lighter. This third type of conventional lighter uses butane gas but uses it to create a post mix flame, not a premix flame.